Restrictive / Mal-Absorptive Procedure:aims to reduce the stomach size and decrease food intake by creating a small stomach pouch and by bypassing 2m of proximal small bowels.
Several types of mal-absorptive procedures are found, but the 2 most performed at COCP are:
Laparoscopic Mini Gastric Bypass
First described by Rutledge in 1997, this new combined procedure also known as One Anastomosis Gastric Bypass (OAGB) or Single Anastomosis Gastric Bypass (SAGB) or Loop Gastric Bypass (LGB) is based on reducing the size of the stomach and connecting the small gastric pouch to the small bowel at the level of the jejunum approximately 2 meters after the end of the stomach.
In this case a single anastomosis is done between a small long gastric tube (also calibrated on an orogastric tube inserted by the anesthesiologist) and the jejunal part of the small bowel. This will necessitate food consumption in very small quantities. Along with the restrictive part, the ingested amount of food will be diverted from the digestive fluid secretions. This bypass of the food will cause an important reduction of the absorption of nutrients and induce weight loss.
This intervention will achieve an almost similar to slightly better results than the classic RYGB, in term of long term weight loss and resolution of co-morbidities. The post-operative morbidity is less than the RYGB.
The main concern remains in the severity of Dumping syndrome in certain cases and the more important mal-absorptive component can be managed by multiple oral supplementations (especially for Iron). To note that it is the only technique that can be amenable to reversibility in case of excessive weight loss or severe malabsorption.
Laparoscopic Roux-En-Y Gastric Bypass
Roux-en-Y gastric bypass (RYGB), commonly called simply “gastric bypass”, is one of the most popularly performed bariatric procedures worldwide and has long been considered the “gold standard” of bariatric surgery. The gastric bypass was first reported in 1967 by Mason and was performed as open surgery for several decades. However, today, it is almost entirely performed laparoscopically.
The operative procedure involves staple dividing the stomach into two chambers, a very small proximal gastric pouch of about 30cc and the excluded distal remnant. The remnant is excluded from alimentary transit. The proximal gastric pouch is (anastomosed) connected to the proximal jejunum (rouxlimb). A second anastomosis is made between the distal roux limb and the proximal jejunum (biliopancreatic limb) that drains the secretions from the excluded gastric remnant, duodenum, liver and pancreas. This connection enables the digestive fluids to meet the ingested food to enable nutrient breakdown and absorption. The distance between the 2 connection can vary by surgeon preference but is generally 50 to 150 cm.
After the procedure is completed, food advances directly from the gastric pouch to the small intestine without passing through the distal portion of the stomach, duodenum and proximal jejunum. This gastric bypass is thought to have several mechanisms of action. It restricts the oral food intake and re-routes the transit of food inducing metabolic and hormonal changes that reduce appetite, increase satiety and energy expenditure.
The maximum effect in terms of weight loss is normally observed during the first two years. During this period of time, morbidly obese patients can lose a good amount of their excess weight. Seventy five to 85% of patients will maintain at least a 50% excess weight loss long-term. Several obesity-associated conditions Different diseases such as type 2 diabetes, hypertension, dyslipidemia, metabolic syndrome, fatty liver disease and obstructed Sleep Apnea will resolve or improve after gastric bypass surgery. In fact, more than 50% of patients with Type II Diabetes will experience normalization of their blood sugar levels and will either be off all of their anti-diabetic medications or markedly less medications.
At high volume bariatric centers, the risk of post-operative complications is low. However, the gastric bypass procedure can result in significant risk of vitamin and mineral deficiencies including Iron, vitamin B12, calcium, vitamin D and folate). Therefore, as with all bariatric procedures, the patients who undergo gastric bypass require life-long surveillance and vitamin and mineral supplementation.
Laparoscopic Single Anastomosis Duodeno-Ileal Bypass(SADI)
Andrés Sánchez-Pernaute was the first to develop this new procedure in 2007. It is a combined procedure that will join the duodenum to the distal small bowel (SADI). It can be associated to a Sleeve Gastrectomy (SADI-S). The first step of the procedure is a restrictive part, by creating a sleeved stomach (Same technique as the LSG). In a second step a major malabsorptive component is added after dividing the stomach pouch at the level of the duodenum to reconnect it to the distal small bowel at a distance between 2.5 to 3 meters from the ileo-caecal valve. In this case, a single anastomosis is done between a small long gastric tube with the pylorus kept in place and the distal part of the small bowel. This will necessitate food consumption in very small quantities.
Along with the restrictive part, the ingested amount of food will be diverted from the digestive fluid secretions. This bypass of the food will cause an important reduction of the absorption of nutrients and induce weight loss.
Initial reports suggest that the excess weight loss 5 years after a SADI procedure remains comparable to the DS at 90% (compared with 50-70% for the sleeve or bypass).
To note that this procedure can be performed as a single stage procedure for initial morbid obesity or as a Redo procedure for weight recidivism. Long term result